it's funny because there's a ton of shitty companies trying to con closeted trans women into taking phytoestrogen supplements as an OTC transition drug. it's well known in trans communities that at best the dosages are too low to do anything and at worst have a straight up negative impact because phytoestrogens have an extremely weak estrogenic effect, so they block up the estrogen receptors and prevent the actual estradiol in your system from doing anything. some recent studies show that at a sufficiently high dosage, they can permanently harm breast development and the like, but the effect/sample sizes are too small to be certain yet (medical research on transition fucking sucks -- there's no funding and they operate on samples of like 10 people at a time).